焊接箱型截面构件在不同焊缝熔深下承载力性能试验研究

Experimental Study on Bearing Capacity of Welded Rectangular Section Members Under Different Weld Penetration Depths

为了有效改善大跨度桥梁中管翼缘焊接箱型截面构件的耐久性问题,提出采用耐候钢代替普通钢的管翼缘箱型截面梁;同时,为了研究耐候钢管翼缘焊接箱型截面构件填充混凝土后,在全熔透和部分熔透条件下的单轴承载力性能,开展了焊接矩形截面在3种不同焊缝熔深下的耐候钢管混凝土截面轴压短柱试验研究;分别测试每个试件在单轴压力作用下的静态应变、动态应变,以及竖向位移和侧向位移;对比构件承载力的试验结果及理论分析结果,得出不同熔深下焊接箱型截面管翼缘组合构件的承载力性能。研究结果表明:1)耐候钢管翼缘焊接箱型截面构件的全熔透焊缝承载力高于部分熔透焊缝承载力。2)构件开裂时的竖向位移值,全熔透构件比部分熔透构件大;不同熔深下构件的横向位移值,测点L4随轴压荷载的增大而增加,测点L3随轴压荷载的增大先增加后减小。3)构件内部混凝土应变值,开裂时全熔透构件比部分熔透构件突变小;构件表面钢材竖向应变,整体受压,且随荷载增大而增大;构件表面钢材横向应变,整体受拉,局部在顶部四角位置受压。

To effectively improve the durability of welded rectangular section members(WRSM)with tubular flange in long-span bridges,the use of weathering steel instead of ordinary steel was proposed.At the same time,to study the axial bearing capacity of WRSM of weathering steel tube flange under full weld penetration and partial weld penetration,the axial compression short columns with welded rectangular section under three different weld penetration depths were studied.Tests of the static strain,dynamic strain,vertical displacement,and lateral displacement of each specimen under uniaxial compression were conducted.By comparing the test results and theoretical analysis results,the bearing capacity of WRSM with different penetration depths was obtained.The results showed that:1)the bearing capacity of full penetration weld of WRSM was higher than that of partial penetration weld of WRSM.2)The vertical displacement of full penetration member was larger than that of partial penetration member.For the lateral displacement of members under different penetration depths,the test point L4 increases with the rise of axial compression load,and the test point L3 first increases and then decreases with the rise of axial compression load.3)For the internal concrete strain value of the member,the abrupt change of the full penetration member was smaller than that of the partial penetration member when it cracks.The vertical strain of the steel on the surface of the member was compressed as a whole and increases with the rise of the load;the lateral strain of the steel on the surface of the member was tensioned as a whole,and locally compressed at the top four corners.